Twitter is testing some redesigned elements, to hopefully drive up engagement even more, the focus of most changes of the past couple of years at the site.
Users have been able to add tweets to their "favorites" for years, but most people aren't aware of the feature or what it does, despite the prominent placing.
This is what Twitter hopes to change and it will do that by changing its name. The site is testing several variations, a button with the label "like" and one with "star" have been spotted, replacing the traditional "favorite."
Favorite, unlike its name would suggest, is more about showing appreciation for a tweet than about adding it to your "collection" like you would bookmark a site.
That's actually a good enough reason for the change, "like" makes it a lot clearer what the button does. Then again, the word is too closely associated with the Facebook like button and people will certainly start thinking that Twitter's "like" does pretty much the same thing.